Optimizing React Rerenders: Tips and Tricks

💡 Today I learned something that changed how I think about performance in React… I was working on a simple search input, and everything seemed fine… until I realized something Every single keystroke was triggering an API call That means: 👉 Too many requests 👉 Unnecessary load on the server 👉 A less smooth user experience That’s when I remembered 𝗱𝗲𝗯𝗼𝘂𝗻𝗰𝗶𝗻𝗴 Instead of calling the API on every key press, I added a small delay. Now, the function only runs when the user stops typing for a moment ✨ The result? Fewer API calls Better performance Cleaner and more efficient code Sometimes, it’s not about big changes… but small improvements that make a real difference Have you ever faced this kind of issue? 👇 #React #WebDevelopment #JavaScript #Frontend #Performance #LearningJourney

just published part 2 of my React internals series , this one covers what actually happens when you call setState and how does re-rendering works. part 1 (initial render): https://lnkd.in/dycpqavw part 2 (re-render): https://lnkd.in/d4tWTwmk #react #javascript #frontend #webdev

📌 Part 8 of 10: A lot of React bugs make more sense once you realize state behaves more like a snapshot than a live variable. That idea sounds small. But once it clicks, a lot of confusing behavior starts making more sense. Why logs can feel misleading. Why updates don’t look immediate. Why handlers sometimes “see” older values than people expect. Once I really understood that, I stopped fighting React as much. I started designing with it instead. What React concept took longer to click for you than expected? #React #ReactJS #StateManagement #JavaScript #FrontendDevelopment #Debugging #TypeScript

react 19 has a new use() api and it breaks one of the oldest rules in react hooks must be called at the top level. always. no conditions, no loops. use() doesn't care. you can call it inside if statements, loops, conditionals - things that were never allowed before. it does two things: - reads a promise (integrates with suspense automatically) - reads context (like useContext, but more flexible) function UserCard({ userPromise }) { const user = use(userPromise); // suspends until resolved return <p>{user.name}</p>; } the catch? create your promises in server components and pass them down - not inside the client component itself, or you'll get an infinite loop on every re-render. it's a small api with a big mental shift. react is clearly moving toward a world where async is first-class - not something you bolt on with useEffect + useState + loading flags. #react #react19 #frontend #javascript #webdev

You’re using useEffect WRONG ⚠️ Most React developers make this mistake daily. useEffect is NOT for everything. Here’s where most devs go wrong: ❌ Using it for derived state ❌ Using it for simple calculations Instead: ✔ Compute values during render ✔ Keep logic simple Have you made this mistake before? Comment YES if you have 👇 #ReactJS #Frontend #WebDevelopment #JavaScript #CleanCode

React Batching: The Subtle Bug Most Developers Miss   A quick React insight 👇  React doesn’t re-render on every state update.  It batches multiple updates together for performance. setCount(count + 1); setCount(count + 1);  You might expect +2, but it results in +1 —  because both updates use the same value. ✅ Correct approach: setCount(prev => prev + 1); setCount(prev => prev + 1);  React state updates are scheduled, not immediate --  and that’s where subtle bugs come from. #reactjs #javascript #frontend

Deeply nested state updates in React are a silent productivity killer. If you've ever spent 10–15 minutes updating one tiny value inside a nested object you already know the pain. I used to mutate nested state directly — until it started affecting performance, debugging time, and even load time optimizations. Here’s a simple mindset shift that made my frontend code cleaner and easier to scale #React #FrontendDevelopment #ReactJS #JavaScript #useReducer #StateManagement #ReactHooks 

💡 𝗧𝗶𝗽 𝗼𝗳 𝘁𝗵𝗲 𝗗𝗮𝘆 — 𝗥𝗲𝗮𝗰𝘁 𝗗𝗶𝗱 𝘆𝗼𝘂 𝗸𝗻𝗼𝘄? In React, 𝗳𝘂𝗻𝗰𝘁𝗶𝗼𝗻𝘀 𝗱𝗲𝗳𝗶𝗻𝗲𝗱 𝗶𝗻𝘀𝗶𝗱𝗲 𝗰𝗼𝗺𝗽𝗼𝗻𝗲𝗻𝘁𝘀 𝗮𝗿𝗲 𝗿𝗲𝗰𝗿𝗲𝗮𝘁𝗲𝗱 𝗼𝗻 𝗲𝘃𝗲𝗿𝘆 𝗿𝗲𝗻𝗱𝗲𝗿. This means passing them as props can trigger unnecessary re-renders in child components. 🔧 𝗕𝗲𝘀𝘁 𝗽𝗿𝗮𝗰𝘁𝗶𝗰𝗲: - Use "useCallback" to memoize functions when passing them down - Only do this when necessary (e.g., with "React.memo" or dependency arrays) Not every function needs memoization—but knowing when it matters is key. #React #ReactJS #FrontendDevelopment #JavaScript #WebDevelopment #PerformanceOptimization #SoftwareEngineering #CodingTips #FullstackDeveloper

React Error Boundaries are basically try/catch for UI rendering. Without one, a single broken component can crash the whole screen. With an Error Boundary, React catches the failure and shows a fallback UI instead. Even better: with react-error-boundary, you can also handle async errors using showBoundary(). You can get example code from my blog: https://lnkd.in/gDYnB7h5 #React #Frontend #JavaScript #WebDevelopment

React performance is not just about fast code — it's about preventing unnecessary re-renders. Many developers focus on building features, but understanding why components re-render is what improves real application performance. Here’s a simple breakdown of: ✔ Why components re-render ✔ Common mistakes causing unnecessary renders ✔ How useMemo, useCallback, and React.memo help Small optimizations create big impact in production systems. What’s your favorite React performance optimization technique? #ReactJS #JavaScript #FrontendDevelopment #WebPerformance #SoftwareEngineering #ReactDeveloper #TechLeadership